Honestly, there were a lot of side-quests. Pretty much any time you had to go do a mission that didn't push the main quest-line forward, was a side-quest. It was in your best interest to do them because you got war assets, but, they weren't mandatory. The game blurred the lines between main and side quests since everything, with few exceptions, was related to the main quest, and that was to be expected. The galaxy was under attack, so there's no time to do things that don't help you. Sure, you had the scenes with your crew, like with Garrus at the Citadel, but it was mostly business.

I've argued this game to death with people who hate the ending or hate the game, and I'm tired of it. I keep reading posts (not yours) and screaming "What the heck are you even talking about? That doesn't make sense!" and I wind up writing an essay about how they're wrong, but in the end it doesn't matter. Just keep on keeping on.